The objective of this four year project is to develop improved techniques for diagnosing, determining the risk for, and monitoring the course of treatment of osteoporosis. To achieve this goal we will undertake four studies. These include ultrasound and DEXA measurements, on human subjects, the construction of a new radiological scanning device for measuring bone density, the construction of a new ultrasound scanner for determining Broadband Ultrasonic Attenuation (BUA) and the Speed of Sound (SOS) in cortical bone, hypothesis of a composite model of bone and of fracture risk. Our human subject studies will test the hypothesis that high levels of correlation can be obtained between cortical and trabecular bone measurements using ultrasound. Human studies will also allow us to follow the course of treatment of patients taking osteoporosis medications. Our new radiological scanner will use the highly sensitive coherent to Compton photon scattering ratio (CSR) technique to measure the "true" volumetric. We will test the hypothesis that right-left differences in the calcaneus and distal radius are good indices of osteoporosis. We will test our new CCSR and ultrasound scanners on human subjects. A model of bone as a composite material made of collagen and mineral will be used to calculate fracture and osteoporosis. We will test our new CCSR and ultrasound scanners on human subjects. A model of bone as composite material made of collagen and mineral will be used to calculate fracture and osteoporosis risks and to plan treatment for those diagnosed with or at significant risk for osteoporosis.